The invention relates in general to antennas and more specifically to a patch antenna having an electromagnetic shield counterpoise.
Electromagnetic signals are transmitted and received through antennas. The selection or design of an antenna for a particular device may depend on a variety of factors including signal frequencies, minimum antenna performance, and available space. In mobile wireless devices, the size and location of an antenna are important considerations for the performance of the antenna. Conventional mobile devices utilize embedded patch antennas such as a Planer Inverted “F” Antenna (PIFA) where a radiating element is positioned parallel to a ground plane formed by a conductive ground layer in a printed circuit board (PCB). The radiating element may be printed within a conductive layer in the PCB or may be formed on a separate component that is attached near the ground layer in the PCB. Conventional patch antenna designs are limited since the location of the ground plane in the PCB as well as other mechanical constraints of the mobile device design limits the potential location and position of the radiating element. Performance characteristics of the patch antenna such as bandwidth and efficiency are closely dependent on the spacing between the ground plane and the radiator element. As a result, the location and position of the PCB in conventional mobile devices limits the potential locations of the radiator element and often results in a larger mobile communication device than otherwise required.
Accordingly, there is need for a patch antenna that maximizes the flexibility in antenna location within a portable communication device and facilitates compact designs of mobile communication devices.